Apparatus for the deformation of metal sheets and preshaped bodies under shock effect in water



P. NEMITZ 3,214,950 ATION OF METAL SHEETS AND PRESHAPED Nov. 2, 1965APPARATUS FOR THE DEFORM BODIES UNDER SHOCK EFFECT IN WATER 2Sheets-Sheet 1 Filed July 25, 1963 0 m F m M .1 W6 J 0/0 =5 f 01$ 0 H ii I a 0/ E 4 w Y w x 5: V: f 2 1 g P u l Y1 M 4 km NWEN 70A Pau/ A/en/Zz W Nov. 2, 1960 P. NEMITZ 3,214,950

APPARATUS FOR THE DEFORMATION OF METAL SHEETS AND PRESHAPED BODIES UNDERSHOCK EFFECT IN WATER Filed July 23, 1963 2 Sheets-Sheet 2 United StatesPatent 3,214,950 APPARATUS FOR THE DEFGRMATION 0F METAL SHEETS ANDPRESHAPED BODIES UNDER SHOCK EFFECT IN WATER Paul Nemitz, Kiel-Fries,Germany, assiguor to MaK Maschinenbau Kiel G.m.b.H., Kiel-Friedrichsort,Germany, a firm Filed July 23, 1963, Ser. No. 297,131 Claims priority,application Germany, Jan. 11, 1963, 55,390; May 11, 1963, 56,795 6Claims. (Cl. 7256) The shaping or deformation metal sheets by shockeffect produced by explosive by forcing a sheet metal disc into thevacuum space of a hollow mould by means of shock waves transmitted bywater is known.

In the case of the shock deformation of heavy and large parts the mouldwith the sheet metal disc placed thereon is lowered with the explosivecharge into a water vessel by means of a crane and after the deformationis lifted out of the water vessel by means of the crane for the purposeof removing the shaped part and inserting another disc and explosivecharge.

These operations require heavy lateral swing-out crane plants even inthe case of medium sized moulds. The knocking off of the ropes or chainsout of the crane tackle is very dangerous in the event of a rope orchain accidentally whipping down on to the charge. Moreover the ropes orchains can be damaged by the shock waves.

In the case of shock deformation under water in vessels sunk into theground strong vibrations are produced in the ground by the shock wavesand cause both the equipment for the shock deformation and alsobuildings in the vicinity of the site where the deformation is beingcarried out, to rock considerably.

It is the object of the present invention to avoid the disadvantages ofthe crane plant and to reduce the vibrations emanating from thedeformation site to tolerable extent.

The invention provides an apparatus for the deformation of metal sheetsand preshaped bodies under shock effect in water in which thedeformation is effected by pressing the part to be deformed into thevacuum space of a hollow mould by means of shock waves transmitted bywater, which comprises a water vessel sunk in the ground, a liftingarrangement arranged underneath said water vessel, a working platformcarried by said lifting arrangement, and a hollow mould as well as aholder frame for an explosive charge mounted on said platform, thehollow mould being lowered into its operating position in the watervessel and raised into its charging position above the water vessel bymeans of said lifting arrangement.

The working platform is preferably hydraulically movable.

The water vessel may have a wall composed of interengaging flangedU-girders (sheet piling) which are held together at the upper edge by aband and are cast with a concrete foundation at their lower end. Thebottom of the water vessel may be provided with impact and shockabsorbent materials above the concrete foundation.

A base, for example of ferro-concrete, may be placed on the foundationand supported by interposed regulatable resilient elements. Theseresilient elements cause the base to vibrate during the deformationprocess and thus reduce the shock wave energy emanating from thefoundation.

The resilient elements may be constructed as air cushions which areconnected with a source of compressed air. The pressure of thecompressed air may be varied according to the load. The space betweenthe base and the foundation may also be filled with compressed air thepressure of which is variable.

In order to reduce the effect of the shock waves on the 3,214,950Patented Nov. 2, 1965 side walls of the deformation vessel and theportion of the foundation which is not screened, the space between thebase and the foundation may be provided with a jacket projecting intothe foundation and acting as a bell which is fixed on the outer edge ofthe base.

Two preferred embodiments of the invention will now be described by wayof example and with reference to the accompanying drawings, in which:

FIG. 1 is a vertical section through a deforming apparatus with raisedworking platform;

FIG. 2 is a top plan view of the working platform on a smaller scale;

dFIG. 3 is a top plan view of a part of the sheet piling, an

FIG. 4 is a cross section through a working platform of modifiedconstruction lowered into the water vessel.

The deformation plant shown in FIG. 1 comprises a water vessel 1 sunk inthe ground and having a wall composed of interengaging flanged U-girders2 (FIG. 3). The U-girders 2 are welded together with a strong steel band4 at the upper edge of the vessel and cast at its lower end with aconcrete foundation 3. Between the concrete foundation 3 and a concretebase 5 with a steel plate 7 placed thereon, a shock absorbent material6, such as wood or inflated pressure tubes are arranged. The concretefoundation 3 and the concrete base 5 are secured against lateraldisplacement by strong anchor bolts 24.

A protecting tube 8 is cast in the concrete foundation 3 and a hydrauliccylinder 9 is inserted therein and guided by means of a flange 11. Thehydraulic cylinder 9 is fed by a conduit 21. A piston rod 10 isassociated with the hydraulic cylinder 9 and carries on its upper end aworking platform 12 composed of sheet metal carriers 12a (FIG. 2)arranged on edge in star shape and firmly welded with a carrier plate13. On the sheet metal carriers 12a wire mats 14 are provided forwalkingon the working platform 12.

A mould 16 is placed on the carrier plate 13 in a guide ring 15. A sheetmetal disc 19 is placed on a drawing die 17 in the mould 16 in a knownmanner and clamped with an annular holder 18. An explosive charge 23 isplaced on a frame 20 and can be electrically ignited by an ignition wire22. The air is exhausted from the mould 16 in a known manner through avacuum conduit 25.

In FIG. 4 the water vessel 1 is again formed from U- girders 2 sunk inthe ground. The bottom of the vessel is provided with an iron concretefoundation 3 A working platform 12 is arranged so that it can be liftedout of the vessel by means of hydraulic cylinders 26. The workingplatform 12 comprises a plate 13 carrying the hollow mould 16 on whichthe sheet metal disc 19 to be shaped is placed. The frame 20 carries theexplosive charge 23 for the shock deformation.

Underneath the working platform 12, a concrete base 34 is arranged whichis supported by air cushioning elements 33, which are placed on afoundation 32. The air cushioning elements 33 are supplied with thenecessary compressed air from a conduit 28 through the intermediary of areducing valve 37.

The space 30 between the base 34 and the foundation 32 is connected withthe source of compressed air by a conduit 29 and can be regulatablysupplied with compressed air. The air from the space 30 flows off aroundthe outer edge of the base 34. For this purpose the base carries ajacket 35 projecting into the foundation and acting as a bell. An airscreen ring 36 forms around the mould 16 in the water compartment of thedeforming apparatus. The outflowing air screen effects a reduction ofthe shock wave effect on the side walls of the vessel 1. Furthermore aweakening of the shock wave effect on the unprotected parts of thefoundation is also attained.

In order to amplify the screening effect an annular conduit 31 known perse can also be provided which is supplied with compressed air through aconnecting conduit 40 and forms another annular air screen 27 in thewater bath having the same effect as that above described.

The base 34 is secured against lateral displacement by guide bolts 38sunk in the foundation.

I claim:

1. An apparatus for the deformation of metal sheets and preshaped bodiesunder shock effect in water in which the deformation is effected bypressing the part to be deformed into the vacuum space of a hollow mouldby means of shock waves transmitted by water, comprising a water vesselsunk in the ground, a lifting arrangement arranged underneath said watervessel, a working platform carried by said lifting arrangement, and ahollow mould as well as a holder frame for an explosive charge mountedon said platform, the hollow mould being lowered into its operatingposition in the Water vessel and raised into its charging position abovethe water vessel by means of said lifting arrangement, the water vesselcomprising a wall composed of interengaging flanged U-girders the upperends of which are held together by means of a band while their lowerends are cast in a concrete base and the bottom of the Water vesselbeing covered with shock absorbent materials.

2. An apparatus for the deformation of metal sheets and preshaped bodiesunder shock effect in water in which the deformation is effected bypressing the part to be deformed into the vacuum space of a hollow mouldby means of shock waves transmitted by water, comprising a water vesselsunk in the ground, a lifting arrangement arranged underneath said watervessel, a working platform carried by said lifting arrangement, and ahollow mould as well as a holder frame for an explosive charge mountedon said platform, the hollow mould being lowered into its operatingposition in the water vessel and raised into its charging position abovethe water vessel by means of said lifting arrangement, the workingplatform in its operating position resting on a base placed on thefoundation and being supported thereon by interposed adjustableresilient elements.

3. An apparatus according to claim 2, wherein the resilient elements areconstructed as air cushions and connected with a supply of compressedair the pressure of which is regulatable according to the load.

4. An apparatus according to claim 3, wherein the space between the baseand the foundation is filled with compressed air the pressure of whichis regulatable.

5. An apparatus according to claim 4, wherein a jacket is arranged inthe space between the base and the foundation and projects into thefoundation thereby forming a bell fixed on the edge of the base andproducing an air screen.

6. An apparatus according to claim 5, wherein a compressed air annularconduit is arranged on the inner periphery of the water vessel outsidethe working space and has small apertures for the escapement ofcompressed air to form a second air screen around the hollow mould.

References Cited by the Examiner UNITED STATES PATENTS 2,935,038 5/60Chatten "113-44 3,136,049 6/64 Throner et al 113-44 CHARLES W. LANHAM,Primary Examiner.

1. AN APPARATUS FOR THE DEFORMATION OF METAL SHEETS AND PRESHAPED BODIESUNDER SHOCK IN WATER IN WHICH THE DEFORMATION IS EFFECTED BY PRESSINGTHE PART TO BE DEFORMED INTO THE VACUUM SPACE OF A HOLLOW MOULD BY MEANSOF SHOCK WAVES TRANSMITTED BY WATER, COMPRISING A WATER VESSEL SUNK INTHE GROUND, A LIFTING ARRANGEMENT ARRANGED UNDERNEATH SAID WATER VESSEL,A WORKING PLATFORM CARRIED BY SAID LIFTING ARRANGEMENT, AND A HOLLOWMOULD AS WELL AS A HOLDER FRAME FOR AN EXPLOSIVE CHARGE MOUNTED ON SAIDPLATFORM, THE HOLLOW MOULD BEING LOWERED INTO